The Silicone Mason Jar Protector Sleeve fits 16oz 1 pint Ball and Kerr jars. It insulates you from hot coffee or tea or the cold of a refreshing summer ice-filled drink in a Ball jar. This reusable FDA grade silicone jacket is 100% non-toxic, plastic-free, waste-free, BPA/BPS-free and phthalate-free. By eliminating the need for single-function bottles or containers that will eventually end up in landfills it can also help reduce your carbon footprint.